Method of producing stippled sheet metal



Oct. 24, 1944. A 1 LANGEL 2,361,039

METHOD 0F PRODUCING STIPPLED SHEET METAL Filed Oct. 13, 1939 INVENTOR.

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ATTORNEY?? Patented Oct. 24, 1944 METHOD OF PRODUCING STIPPLED SHEET METAL Adrien L. Ingel, Chicago, Ill., assignor to Chicago Metallic Manufacturing Company, Chicago, Ill., a corporation of Illinois Application October 13, 1939, Serial No. 299,323

1 Claim.

This invention relates to the method of producing stippled sheet metal of a novel type in which projections are provided at irregular positions throughout the face of the sheet. such projections being in the form of oisets produced by a distortion of the metal by pressure on its opposite faces, such pressure being applied in any suitable manner, as by toothed rollers between which the sheet of metal is passed, the projection at one face of the metal being accompanied by a depression at the same general position on the other face of the sheet. It is the object of the invention to provide a novel method of producing the sheet.

This novel form of sheet metal is designed particularly for use in the production of baking pans. though it may be used for any desired purpose. It has been found when baking pans formed of this type of metal are employed, that the grease applied to the face of the pan for keeping the baked -product from sticking to the pan is kept in place in the hollows of the metal with the result that the grease is not able to ow out of position even though a portion of the pan may be out of true horizontal position. It has been found also that the dough at many points is held out of intimate contact with the metal at the deepest portions of the depressions between the projections so as not to displace the grease from such depressions. At the same time, the configuration of the sheet is such as the enable the gases formed in the depressions to escape through the crevices between the projections so as to encourage effective baking.

It is the object of this invention to improve products and methods of this type in sundry details hereinafter pointed out. The preferred means by which the improvements have been attained are illustrated in the accompanying drawing, in which- Fig. 1 is a perspective view of a piece of sheet metal embodying the improved construction;

Fig. 2 is a face view'of a portion of such sheet Referring now to the several figures of the drawing, I0 indicates a sheet of metal having a series of projections irregularly spaced thereon with irregularly shaped depressions between the projections. As is clearly shown in Fig. 3, which is presented as a typical showing of a cross section through the sheet, the sheet I0 is provided with projections II at one face and projections I2 at the opposite face, such projections being rounded at their tips and rounded at their base portions, the projections being in the form of oisets of the body of the metal, the projection at one face of the metal being positioned opposite to a depression at the other face of the metal. The arrangement is such that a baking pan formed from the metal is adapted to receive grease into the depressions which are of such depth as to hold the grease in position and to prevent it from ilowing out of position even though the pan is tipped slightly from the horizontal. The conguration of the face of the sheet is such that a piece of dough is held in slightly elevated position so as normally to prevent contact between the dough and the deepest portions of the depressions between the projections. This permits the grease to remain distributed over the entire face of the bottom of the pan.

When a loaf is in process of being baked in such a pan, the hot gases formed in the depressions are enabled to escape readily along the crevices between adjacent projections so as to insure effective baking conditions.

For producing the novel form of sheet metal asshown and described, a pair of rollers I3 and I4 are rotatably mounted in position by means of shafts I5 and I6, or in any other suitable manner, whereby the rollers cooperate with each other for a pressing operation as hereinafter described. As is clearly shown in Fig. 5, the face of each of the rollers I3 and I4 is provided with a series of outwardly projecting pins or lugs I1 which are provided in substantially radial position at the entire face of each of the rollers.

With the toothed rollers I3 and I4 mounted in cooperative relation, a plain piece of sheet metal is passed between thel rollers so as to cause the teeth or lugs I1 to form aligned depressions scattered over the whole face of the sheet, the teeth or pins I1 of one roller being held in staggered position circumferentially with respect to the teeth -or pins of the other roller for securing the desired result., After the sheet has been passed between the rollers in this way, it is then passed a plurality of times in dierent angular positions between the rollers for causing the distortion of the body of the sheet at irregularly positioned points, whereby a stippled eiIect is produced comprising alternate projections and` depressions throughout both faces of the piece of sheet metal. In the arrangement shown,.the depressions are of a depth corresponding substantially to the thickness ofth sheet metal, although the depressions may be either shallower or deeper as may be desired.

In the preparation of stippled sheet metal in this manner, eiective results have been had by the use of rollers approximately seven inches in diameter, having rows of pins or lugs I1 longitudinally of the rollers at intervals of abouta quarter of an inch circumferentially of the rollers, with such pins about one-sixteenth of an inch in width longitudinally oi the rollers and spaced about three-sixteenths of an inch apart in the longitudinal rows. Satisfactory results have been attained by passing a sheet from six to ten times between the rollers in diierent angular positions as above suggested.

While the process by which the sheets have been produced as outlined is preferred, it is to be understood that the invention is not to be limited to the process as set forth except so far as the claim may be so limited, it being understood that changes might well be made without departing from the spiritv of the invention.

I claim: The method of producing a stippled eliect in la sheet of metal, which comprises feeding the sheet edgewise in a selected angular position between cooperating pressure devices for producing a series of projections aligned with each other on each face of the sheet and separated from each other by intervening depressions aligned in the same direction, and then feeding the sheet between said pressure device a plurality of times additionally with the sheet at each successive treatment advanced at a different angle as compared with previous treatments whereby successive treatments of the sheet by largely breaking down and deforming previously formed rows of projections eliminate almost completely any regularity in the arrangement of said projections.

ADRIEN L. LANGEL. 

